CLO19-024: Risk of Atrial Fibrillation and Pulmonary Toxicities in Patients With Chronic Lymphocytic Leukemia or Small Lymphocytic Lymphoma Treated With Ibrutinib

Abstract

Background: Bruton’s tyrosine kinase (BTK), a kinase downstream of the B-cell receptor, involves in the B cell survival and proliferation and has become an attractive therapeutic target. Ibrutinib is an oral potent, covalent inhibitor of BTK and hence employed in many hematologic malignancies. We performed a systematic review and pooled analysis of randomized controlled trials (RCTs) to determine the risk of atrial fibrillation (AF) and pulmonary toxicities among patients treated with ibrutinib. Methods: We performed a comprehensive literature search using MEDLINE, EMBASE databases, and meeting abstracts through September 2018. Phase 3 RCTs that mention AF and pulmonary toxicities as adverse effects were incorporated in the analysis. Mantel-Haenszel method was used to calculate the estimated pooled risk ratio with 95% CI. Random effects model was applied. Results: 4 phase III RCTs with a total of 1,383 patients with chronic lymphocytic leukemia or small lymphocytic lymphoma were eligible. Studies comparing Ibrutinib (I) vs ofatumumab, I vs chlorambucil, I+ bendamustine (B)+ rituximab (R) vs placebo + B+ R, and I vs R were included in the analysis. The AF incidence was 41 (5.686%) in the ibrutinib group vs 8 (1.208%) in the control arm. The relative risk (RR) for AF was statistically significant at 3.825 (95% CI: 1.848–7.917; P<.0001) and RD was 0.041 (95% CI: 0.023–0.059; P<.0001). The RR of all-grade side effects was as follows: cough, 1.133 (95% CI: 0.724–1.773; P=.584); edema, 1.375 (95% CI: 0.943–2.006; P=.098); pneumonia, 1.227 (95% CI: 0.884–1.703; P=.221); and upper respiratory infections (URI), 1.075 (95% CI: 0.809–1.429; P=.616). The RR of high-grade side effects was as follows: cough, 0.373 (95% CI: 0.063–2.209; P=.277); edema, 1.232 (95% CI: 0.199–7.649; P=.822); pneumonia, 1.277 (95% CI: 0.847–1.926; P=.243); and URI, 1.555 (95% CI: 0.239–10.127; P=.644). Conclusion: Our meta-analysis demonstrated that patients on ibrutinib noted a significant increase in the risk of atrial fibrillation with a relative risk of 3.825. However, the risk of pulmonary toxicities was not statistically increased in the ibrutinib group.